As someone stated in another answer, the problem could have been imported from latin. I say what happens in other idioms, it always helps me to realized which ways to take for the logical construction of phrases.
In spanish (latin), you should not use "I" and someone, because is non polite to construct the phrase that way. You are being more important in the phrase so you place yourself first. This speak badly of you. Don't know if that's the exact reason in english but it could be. You resolve a lot of problems writing in that way.
In the case you propose, I see this (I'm not native english, so please educate me):
"Sarah and we are going to build an aircraft."
I help myself with punctuation, it gives just the pauses I need to realize what should be appropriate sometimes. So:
- Sarah and I, we are going to build an aircraft.
- Sarah and we, we are...
- Sarah and us, we are...
- Sarah and ourselves, we are...
And following the counsel,
- I/Me and Sarah, are going to build an aircraft.
- We and Sarah, are...
- Us and Sarah, are...
- Ourselves and Sarah, are...
The only phrase that doesn't sound or looks odd given the examples is WE, but I think "Sarah and we are going..." it's pretty ambiguous. If you use the comma, you'll see that using it after we, left us with "are going to build an aircraft"... in spanish could be done because the pronoun is tacit but don't know if in english you could do that so simply.
If I was you, I'd use "We and Sarah are going..."
or I use the comma as in "Sarah and we, are going..."
My two cents.